How MBBR sewage treatment plants can adapt to different water qualities

MBBR (moving bed biofilm reactor) sewage treatment plants can achieve self-adaptation to different water qualities in the following ways:

Self-regulation of microbial populations
Diverse microbial communities
The fillers in the MBBR device provide a large number of attachment surfaces for microorganisms, and complex and diverse microbial communities will be formed during long-term operation. When the sewage quality changes, such as the increase in the concentration of organic matter in the influent or the change in the type of pollutants, different types of microorganisms will dynamically adjust in the biofilm according to their own needs for nutrients and survival advantages. The originally disadvantaged microbial population that can decompose new pollutants may gradually proliferate, while the number of microbial populations that are not adapted to the new environment may decrease. This natural succession and adaptive regulation of microbial communities enables the device to cope with various types of pollutants.

Induced enzyme mechanism of microorganisms
Microorganisms have the ability to produce induced enzymes. When new pollutants enter the sewage, microorganisms can synthesize corresponding induced enzymes to decompose them after contacting these new substrates. For example, when a certain special organic compound appears in the sewage, microorganisms can produce specific enzymes to catalyze the decomposition reaction of the compound, so that the MBBR device has a certain treatment capacity for the newly emerged pollutants.

Flexible operation parameter adjustment
Aeration control
According to the different influent water quality, the aeration intensity can be flexibly adjusted. For high-concentration organic sewage, appropriately increasing the aeration intensity can increase the dissolved oxygen content in the water and meet the needs of aerobic microorganisms to decompose organic matter in large quantities. For low-concentration sewage, the aeration intensity can be reduced to avoid excessive aeration causing energy waste and abnormal growth of microorganisms. At the same time, aeration methods (such as microporous aeration, surface aeration, etc.) can also be selected or switched according to the characteristics of water quality.

Hydraulic retention time (HRT) and reflow ratio adjustment
Adapt to different water qualities by changing HRT and reflow ratio. If the influent water quality is poor and the pollutant concentration is high, the HRT can be appropriately extended to allow the sewage to have more sufficient time to contact with microorganisms and fillers in the device to improve the treatment effect. For some sewage containing difficult-to-degrade substances, a reasonable setting of the reflow ratio can allow the sewage to go through the biological treatment process multiple times to enhance the treatment effect.

Filler characteristics and optimization
Selection and replacement of fillers
Fillers of different materials and shapes have different microbial attachment properties and sewage treatment capabilities. Appropriate fillers can be selected according to the characteristics of the influent water quality. For example, for sewage containing more suspended solids, fillers with larger pores and less prone to clogging can be selected; for sewage that needs to enhance denitrification, fillers with special structures or materials can be used to promote the growth of nitrification and denitrification bacteria. In addition, if it is found that the existing fillers are not effective for specific water quality treatment, more suitable fillers can be partially or completely replaced.

Filler filling rate adjustment
Adjust the filler filling rate in the reactor according to the water quality and treatment requirements of the sewage. For high-load sewage, increasing the filler filling rate can provide more microbial attachment area and enhance the treatment capacity; while for low-load sewage, appropriately reducing the filling rate can avoid problems such as clogging caused by excessive growth of microorganisms.

Coordination of pretreatment and post-treatment links
Optimization of pretreatment links
MBBR devices are usually combined with appropriate pretreatment processes. For example, when the influent contains a large amount of suspended matter or grease, pretreatment facilities such as screens, grit chambers, and grease traps can be set up before the MBBR to remove these substances that may interfere with the normal operation of the MBBR, so that the sewage quality entering the MBBR is more stable, which is conducive to the adaptive operation of the device. At the same time, for the abnormal pH value of the influent, the pH can be adjusted in the pretreatment stage to create a suitable growth environment for the microorganisms in the MBBR.

Supplementary post-treatment links
The post-treatment link can be adjusted according to the final effluent water quality requirements and the changes in the influent water quality. If the sewage after MBBR treatment still cannot meet the discharge standards, deep treatment processes such as activated carbon adsorption and advanced oxidation can be added. The post-treatment process can be used as a supplementary means to make up for the shortcomings of MBBR in treating certain special water qualities or high-demand effluent standards, thereby improving the adaptability of the entire sewage treatment system to different water qualities.

If you need a high-quality MBBR sewage treatment plant, please contact BioCell Environmental Technology for more questions.

https://www.biocell-enviro.com/